Electrical winding



7 y 2, 1939- H. o. STEPHENS 2,157,031

' ELECTRICAL WINDING I Filed March 1, 1938 Fig. I.

II-f .iil illlllllll illlll Inv enter Howavd 0. Stephen 5 b 5 His Attonneg,

Patented May 2, 1939 UNITED STATES ELECTRICAL WINDING Howard 0. Stephens, Pittsfield, Mass, assignor to General Electric Company, a corporation of New York Application March 1, 1938, Serial No. 193,321

4 Claims.

My invention relates to electrical windings such as are commonly used in electrical induction apparatus such as transformers and reactors, and it is particularly applicable in con- 5 nection with windings including spaced disk coils connected in series by cross connections alternately connecting the inner and outer turns of adjacent coils. Where a cross connection meets a coil, it passes over one of the edges or 10 corners of an adjacent turn of the coil and its insulation may be damaged and weakened by rubbing against this edge of the adjacent turn. The rubbing and damage may be caused by vibration during shipment, by variations in elec- 15 tromagnetic forces during operation, or by other causes. The turns of the coils are necessarily clamped tightly together so that any rubbing of the cross-over insulation against the corners of the adjacent turns should be avoided. In accordance with the invention a smooth, flat sheet of tough insulating material is provided between each cross-over and the adjacent turns of the two coils connected by the cross-over, the insulating sheet engaging the spacers between the coils to hold it securely in position and being so formed as not to interfere appreciably with circulation of a cooling medium between the coils.

The invention will be better understood from the following description taken in connection 30 with the accompanying drawing in which Fig. 1 is a side view of a winding having cross-over coil connections protected by insulating sheets formed and assembled in accordance with the invention; Fig. 2 is an enlarged face view of a small portion 35 of one edge of one of the coils of the winding shown in Fig. 1; Fig. 3 is .an enlarged perspective view of one of the cross-over protecting insulating sheets; and Fig. 4 is a perspective View of a modified form of insulating sheet.

Like reference characters indicate similar parts in the different figures of the drawing.

The electrical induction apparatus, shown in Fig. 1, includes a magnetic core l having a winding leg H and surrounded by a winding I2. The

5 winding !2 is formed of a stack of disk coils [3 held in spaced relation by radial spacing strips M. The coils [3 are connected in series by cross connections [5 between the outer turns of adjacent coils and cross connections I6 between the 50 inner turns of adjacent coils.

Each of the cross connections l5 and I6 passes over a corner or edge of the adjacent turn of each of the coils which it connects and it is protected from rubbing and abrasion on these ad- 55 jacent turns by an interposed, smooth sheet I! of tough insulating material such as pressboard. Each of these sheets ll of insulating material is formed in accordance with the invention to include a body portion l8 and suitable projections 19 for engaging the adjacent spac- 5 ing strips l4 to hold the sheet ll securely in position under its cross-over connection l5 or It. In the form of the invention shown in Fig. 3 the projections [9 are of the same Width as the thickness of the spacing strips H5 and they ex 10 tend under the coil turns connected by the crossover so that they effectively prevent any displacement of the insulating sheet I! in a direction perpendicular to the coils. The body portion 18 of the insulating sheet H is of such length that its transverse end edges 25 are close to the adjacent spacing strips [4 so that displacement of the insulating sheet in a direction along the edges of the coils I3 is efiectively prevented. The projections H), the edges or shoul- 20 ders 2i and the overlying cross-over E5 or l6 secure the insulating sheet IT in position and efiectively prevent displacement of the sheet in any direction. The insulating sheets l'l are preferably provided with openings 2| to permit free fiow of insulating and cooling fluid such as oil or air through the spaces between the coils l3.

The modified form of insulating sheet ll, shown in Fig. 4, includes a projection [9 on one end which extends completely around one of the spacing strips l4 so that displacement of the sheet is effectively prevented without the necessity of any shoulder 20 at the other end of the sheet. In this particular form of the insulating sheet ll, the projection H! which surrounds a spacing strip I l provides two oppositely disposed shoulders 29 for preventing displacement in either direction along the edges of the coils. Insulating sheets ll of still other contours may be easily provided with spacer strip engaging portions which will efiectively prevent displacement.

The insulating sheets ll formed in accordance with the invention may be very easily and quickly formed by simple cutting or punching operations and they may be very easily and quickly assembled with the winding, no provision for securing them in position being necessary other than their engagement by the cross-over connections i5 and I8 and the spacing strips [4.

The invention has been explained by describing and illustrating preferred forms and arrangements thereof but it will be obvious that changes may be made without departing from the spirit of the invention and the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States, is:

l. The combination in an electrical winding, of two spaced disk coils, radial spacing strips between said coils, a cross-over connection between said coils, and an insulating sheet between said cross-over connection and adjacent coil turns, the insulating sheet having spacing strip engaging projections and transverse end shoulders to prevent displacement of the sheet.

2. The combination in an electrical winding, of two spaced disk coils, radial spacing strips between said coils, a cross-over connection between said coils, and an insulating sheet between said cross-over connection and adjacent coil turns, the insulating sheet having transverse edges engaging said spacing strips to prevent displacement of the sheet.

3. The combination in an electrical winding, of two spaced disk coils, radial spacing strips between said coils, a cross-over connection between said coils, and an insulating sheet between said cross-over connection and adjacent coil turns, the insulating sheet having spacing strip engaging projections to prevent displacement of the sheet, and the sheet having openings to permit flow of an insulating fluid through the space between the coils.

4. The combination in an electrical winding, of two spaced disk coils, radial spacing strips between said coils, a cross-over connection between said coils, and an insulating sheet between said cross-over connection and adjacent coil turns, the insulating sheet having a body portion with end shoulders engaging the spacing strips and having projections extending between spacing strips to prevent displacement of the sheet.

HOWARD O. STEPHENS. 

